Hair smoothing is understood as meaning the straightening of wavy hair. For this, mechanical methods using heat in the form of e.g. smoothing irons in combination with haircare agents are understood just as much as chemical methods which penetrate into the structure of the hair. In the case of the chemical hair smoothing agents, also called hair relaxers, a distinction is made between agents based on thioglycolates, i.e. a reversed permanent wave, and the basic (lye-based) and the so-called non-basic (no-lye) relaxers. The latter use guanidinium hydroxide and are supposed to be less skin-irritating. They generally consist of two components, a cream base and a likewise basic activator, a concentrated solution of guanidinium carbonate in water.
The former are preparations based on sodium, potassium or lithium hydroxides. Depending on the hair structure, different amounts of hydroxide are incorporated into creams or gels in order to ensure simple handling coupled with adequate protection of the scalp at the same time.
However, it is common to all of these chemical hair smoothers of the prior art that they are firstly very aggressive towards the scalp and can lead to irritations, and secondly the application leads to significant damage of the hair. The hair becomes split and brittle to an extent which cannot be compensated for by subsequent treatment with conditioners.
The object of the present patent application was therefore to provide chemical hair smoothing agents which have less hair damage than the current market products. At the same time, these hair smoothing agents should have greater skin compatibility and thus be easier to use, including by the end customers.